What's new with clopidogrel?

Clopidogrel, an antiplatelet pro-drug, is indicated for use in the prevention of blood clot formation within the arteries following acute coronary syndromes or percutaneous coronary interventions. Recent controversies surrounding clopidogrel-led treatment have resulted in increased focus on its use in a variety of clinical settings. Two recently published BMC Medicine articles provide further evidence to help weigh up the clinical efficacy and potential risks associated with clopidogrel use.

Clopidogrel may be prescribed either exclusively, or in combination with acetylsalicylic acid (Aspirin) as a treatment strategy aimed at preventing the formation of blood clots. This combination strategy has been previously shown to have a diminished effect in preventing blood clot formations for up to 30% of patients. In a research article in BMC Medicine, Neubauer and colleagues show that through implementation of a novel therapeutic plan, including testing for lowered drug responses and increased drug dosages, this reduced effect may be mitigated, leading to an increased probability of successful treatment for these patients. 

Another combination of drugs commonly prescribed is clopidogrel together with proton pump inhibitors (PPIs) in patients who have cardiovascular symptoms and also a risk of gastro-intestinal (GI) bleeding. Recent statements from various regulatory groups have warned about the potential for clinically significant interactions between these two drug classes, thus current advice is to avoid prescribing patients both drugs. In a systematic review in BMC Medicine, Brophy and Lima investigated all studies reporting a clinical outcome when treating patients with both clopidogrel and PPIs alongside a rigorous appraisal of the study methodologies implemented to appraise the potential for bias. The authors found that it was only low quality studies (i.e. with an increased risk of bias) that were more likely to report the potential negative outcome of this combined PPI and clopidigrel therapy. The authors conclude that high quality evidence for a clinically significant relationship is as yet lacking, so with further research it may prove possible to treat patients with both drugs.

The findings from these studies may open the door to fresh debate over whether clopidogrel may be used safely and effectively in tandem with other drugs (such as PPIs) highlighting the importance of testing the validity of the current findings in this controversial field.

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